The present invention pertains to a novel method for producing improved preformed expansion joint filler and other products from cellulosic fiberboard.
In accordance with a generally practiced procedure for producing cellulosic fiberboard expansion joints filler, cellulosic fiberboards are conveyed through a bath containing cut-back asphalt. The boards are then stacked with slats between each board in order to permit both air drying and oven drying in order to evaporate the naphtha or other solvent used in cutting the asphalt. The dry boards are then restacked in units for shipment.
The discharge of solvent into the air results in ecological imbalance of the atmosphere, and attempts have been made in that regard to produce cellulosic fiberboard impregnated with asphalt which would result in a minimization or even elimination of the discharge of solvent into the air. Processes involving the use of an odorless solvent are expensive and require the continuation of dipping and handling costs. Likewise the collection and condensation of the solvent fumes from drying ovens involves a major capital investment while continuing the dipping and handling costs.